Schlumberger

Technical Paper: An Innovative Dielectric Dispersion Measurement for Better Evaluation of Thin Layered Reservoirs Applied in a South Italy Well

Society: Other
Paper Number:
Presentation Date: 2011
 

Abstract

Modelling and exploiting very thin layered reservoirs is challenging and requires the capability to describe complex petrophysical models and to simulate accurate distributions of the petrophysical properties; this process often benefits from the availability of technologically advanced, fit-for-purpose measurements.

A new dielectric dispersion tool was successfully field tested in thin layered low resistivity pays, whose layer thickness was always below the resolution capabilities of the standard logging tools; the high resolution measurements provided by new dielectric dispersion tool comes with the continuous measurement of dielectric dispersion at multiple frequencies in the MHz to GHz range.

This paper describes the innovative petrophysical interpretation of a thin layered turbiditic sequence in the Pleistocenic levels of the Iblean Offshore (Sicily); the sequence was characterized by a high degree of variation of the layers’ thickness (from meters down to laminations), therefore the conventional interpretation was unable to explain the actual gas production rates in thin layers.

In order to achieve the best petrophysical characterisation, a full set of WL logs was acquired, together with the new tool to be tested (dielectric dispersion tool) and wireline formation tester. A core was also cut in thin layers. During the interpretation, the gas shows from the masterlog were used to improve the definition of the zones with potential gas presence.

The previous interpretation was improved by the integration of the broad frequency dielectric spectra made available by the dielectric dispersion tool, together with a suitable petrophysical dispersion model used to fully exploit the total tool measurements. The availability of a high resolution quantitative evaluation of the shale content and water filled porosity improved the definition of the reservoir geometry and petrophysical properties providing a better definition of SW profiles and a more robust evaluation of GOIP.

Related services and products

 
Request More Information